buffer_get.c (1272B)
1 /* Public domain. */ 2 3 #include "buffer.h" 4 #include "byte.h" 5 #include "error.h" 6 7 static int oneread(buffer_op op,int fd,char *buf,unsigned int len) 8 { 9 int r; 10 11 for (;;) { 12 r = op(fd,buf,len); 13 if (r == -1) if (errno == error_intr) continue; 14 return r; 15 } 16 } 17 18 static int getthis(buffer *s,char *buf,unsigned int len) 19 { 20 if (len > s->p) len = s->p; 21 s->p -= len; 22 byte_copy(buf,len,s->x + s->n); 23 s->n += len; 24 return len; 25 } 26 27 int buffer_feed(buffer *s) 28 { 29 int r; 30 31 if (s->p) return s->p; 32 r = oneread(s->op,s->fd,s->x,s->n); 33 if (r <= 0) return r; 34 s->p = r; 35 s->n -= r; 36 if (s->n > 0) byte_copyr(s->x + s->n,r,s->x); 37 return r; 38 } 39 40 int buffer_bget(buffer *s,char *buf,unsigned int len) 41 { 42 int r; 43 44 if (s->p > 0) return getthis(s,buf,len); 45 if (s->n <= len) return oneread(s->op,s->fd,buf,s->n); 46 r = buffer_feed(s); if (r <= 0) return r; 47 return getthis(s,buf,len); 48 } 49 50 int buffer_get(buffer *s,char *buf,unsigned int len) 51 { 52 int r; 53 54 if (s->p > 0) return getthis(s,buf,len); 55 if (s->n <= len) return oneread(s->op,s->fd,buf,len); 56 r = buffer_feed(s); if (r <= 0) return r; 57 return getthis(s,buf,len); 58 } 59 60 char *buffer_peek(buffer *s) 61 { 62 return s->x + s->n; 63 } 64 65 void buffer_seek(buffer *s,unsigned int len) 66 { 67 s->n += len; 68 s->p -= len; 69 }